SAML and SSO with Marketo Landing Pages

We are wanting to build a Marketo landing page with a form for our sales reps to enter customer data for a campaign we will be running, but we are needing the landing page to be secure. We are wanting the sales reps to be able to access the link to landing page via our intranet and want them to only have to be able to sign on one time via the intranet to be able to securely access the form on the Marketo landing page. Does anyone have experience with leveraging SAML to create a SSO experience for a Marketo landing page in the way that I'm describing? Any additional ideas/insight here would be greatly appreciated!